1. Field of the Invention
This inventions relates to a method for producing a wear-detection probe for a brake lining material in a vehicle such as a motorcar.
2. Statement of the Prior Art
A brake for a vehicle generates a braking force by pressing a lining material such as a shoe lining in a drum brake or a brake pad in a disc brake on a rotor. It is possible to improve the safety of the brake by detecting the amount of wear of the lining material and generating a warning signal before the lining material has been overworn.
As means for detecting a usable limit of brake lining material with respect to wear, there is a contact type device which has a probe provided in or near the brake lining material with a conductor which is contacted with the rotor when the brake lining is worn by a predetermined amount and which turns on a warning light to indicate wear of the lining material when the conductor is contacted with the rotor.
For convenience of explanation, a conventional contact type wear-detection probe 100 for brake lining material will be described below by referring to FIG. 10.
The probe 100 comprises a detection part 101a having an end face of a detection conductor 101 connected to a controller (not shown) and a housing 102, made of a resin material, for receiving the detection part 101. The probe 100 is secured to a back metal D of a brake lining material C with the detection part 101a being inserted into the brake lining material C. In the probe 100 shown in FIG. 10, the detection part 101a is contacted with a rotor R which rotates by wheels and then conducts an electrical current to the controllers when the brake lining material C is worn by a given amount.
However, it was very difficult in the conventional contact type wear-detection probe to properly place the detection part 101a having the end face of the detection conductor 101 at the predetermined position in the housing 102, since the detection conductor 101 made of electrical wire is inserted into the housing 102. It will be impossible to accurately detect the time when the residual thickness of the brake lining material reaches a predetermined wear limit if the detection part 101a is not disposed at the predetermined position. Accordingly, the conventional probe has had a problem with reliability.
In addition, the detection conductor 101 has a tendency to incline and readily fall out of the housing 102 it is merely inserted in the housing 102.